dbSNP rs781745158: FBN2:p.Ala689Gly (chr5-128374657-G-C) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_001999.4(FBN2):c.2066C>G(p.Ala689Gly) variant causes a missense change. The variant allele was found at a frequency of 0.00000274 in 1,461,676 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

FBN2
NM_001999.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 6.95

Variant links:

Genes affected

FBN2 (HGNC:3604): (fibrillin 2) The protein encoded by this gene is a component of connective tissue microfibrils and may be involved in elastic fiber assembly. Mutations in this gene cause congenital contractural arachnodactyly. [provided by RefSeq, Jul 2008]

FBN2 links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FBN2	NM_001999.4 link	c.2066C>G	p.Ala689Gly	missense_variant	Exon 15 of 65	ENST00000262464.9	NP_001990.2	P35556-1
FBN2	XM_017009228.3 link	c.1913C>G	p.Ala638Gly	missense_variant	Exon 14 of 64		XP_016864717.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
FBN2	ENST00000262464.9 link	c.2066C>G	p.Ala689Gly	missense_variant	Exon 15 of 65	1	NM_001999.4	ENSP00000262464.4	P35556-1
FBN2	ENST00000508989.5 link	c.1967C>G	p.Ala656Gly	missense_variant	Exon 14 of 33	2		ENSP00000425596.1	D6RJI3
FBN2	ENST00000511489.1 link	n.287C>G		non_coding_transcript_exon_variant	Exon 3 of 6	3

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

0.00000274

AC:

AN:

1461676

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

727142

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000360

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Congenital contractural arachnodactyly

Uncertain:1

Feb 05, 2016

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces alanine with glycine at codon 689 of the FBN2 protein (p.Ala689Gly). The alanine residue is highly conserved and there is a small physicochemical difference between alanine and glycine. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a FBN2-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). In summary, this is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.29

BayesDel_addAF

Uncertain

0.10

BayesDel_noAF

Benign

-0.090

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.65

D;.;D;T

Eigen

Uncertain

0.47

Eigen_PC

Uncertain

0.52

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Benign

0.79

T;.;.;T

M_CAP

Benign

0.038

MetaRNN

Uncertain

0.50

T;T;T;T

MetaSVM

Uncertain

0.15

MutationAssessor

Benign

1.1

L;.;L;.

PrimateAI

Uncertain

0.58

PROVEAN

Uncertain

-2.8

D;.;D;D

REVEL

Uncertain

0.57

Sift

Benign

0.033

D;.;D;D

Sift4G

Benign

0.14

.;.;.;T

Polyphen

0.64

P;.;P;D

Vest4

0.60

MutPred

0.63

Gain of disorder (P = 0.0283);.;Gain of disorder (P = 0.0283);.;

MVP

0.59

MPC

0.67

ClinPred

0.98

GERP RS

4.5

Varity_R

0.25

gMVP

0.41

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over